Governor with adjusting means

ABSTRACT

The invention provides means for adjusting governor regulation in governors of the type having flyweights and an interacting governor spring. The adjusting means comprise a resilient lever having a portion thereof cantilevered over a fulcrum member, which is adjustable to vary the length and the spring rate of the cantilevered portion of the lever. The fulcrum member is selectively positionable to provide the desired spring rate in the cantilevered portion of the lever which bears on the governor spring, and provides the desired governor regulation within a relatively narrow range of tolerance.

United States Patent [191 Staebler May 27, 1975 [5 GCVERNOR WITH ADJUSTING MEANS Primary Examiner-James J. Gill Attorney, Agent, or Firm-Phillips, Moore, I P l.St bl D l ,Ill. [75] mentor J ae un ap Werssenberger Lempio & Strabala [73] Assignee: Caterpillar Tractor Co., Peoria, Ill.

22 Filed: Dec. 17, 1973 57 ABSTRACT [21] Appl. No.2 425,219 The invention provides means for adjusting governor regulation in governors of the type having flyweights [52] U 8 Cl 73/543, 73/546 and an interacting governor spring. The adjusting [51] Gosd 13/20 means comprise a resilient lever having a portion [58] Fie'ld 541 543 thereof cantilevered over a fulcrum member, which is 3 adjustable to vary the length and the spring rate of the cantilevered portion of the lever. The fulcrum mem- [56] References Cited ber is selectively positionable to provide the desired spring rate in the cantilevered portion of the lever UNITED STATES PATENTS which bears on the governor spring, and provides the 2,507,689 i i :2 desired governor regulation within a relatively narrow 3,185,141 1 irac iet a. ran 6 f 1 3,400,697 9/1968 Cupit et al. 73/546 X g o eran 5 Claims, 4.Drawiing Figures PATENTED MY 27 1915 SHEET GOVERNOR WITH ADJUSTING MEANS BACKGROUND OF THE INVENTION This invention relates to a governor for regulating engine speed. In particular, this invention relates to such a governor having improved adjusting means for adjusting governor regulation.

Governors for regulating engine speed frequently operate through the interaction of flyweights and an opposing governor spring. Typical of such governors is the governor described in U.S. Pat. No. 3,145,702 to J. H. Parks, issued Aug. 25, 1964, and the hydromechanical governors described in US. Pat. Nos. 2,961,229; 3,145,624; and 3,534,660, issued respectively on Nov. 22, 1960 to J. H. Parks; on Aug. 25, 1964 to J. H. Parks, et a1; and on Oct. 20, 1970 to Glassey, et al, all of common assignment herewith.

In governors of this type, the flyweights are mounted on a member which rotates at a speed proportional to the engine speed, and assume a position consistent with the centrifugal force supplied by the rotating member. The flyweights interact with the opposing spring according to the load placed on the engine at a particular speed, and determine the position of a fuel control member such as a fuel pump rack bar. Constant speed operation is achieved when the rack bar is positioned to supply fuel to the engine to operate it at a speed which rotates the flyweights with sufficient centrifugal force to counteract the force of the opposing governor spring.

It is well known in the art that a certain amount of governnor regulation or speed droop is required for governor stability, and this regulation is usually designed into the governnor mechanism. On applications where regulation is not so critical, such as in tractors and other earthmoving vehicles, the regulation may be as much as with a lenient tolerance on each side of the nominal regulation providing a range of tolerance. In certain other applications, however, a governor with a lower nominal regulation is required, and variations must be held to a minimum. For example, where a governor is employed to regulate the speed of a diesel engine running a generator, a governor with at least 3% regulation within a narrow tolerance is required.

It is commonly difficult in practice to ascertain whether the particular spring and flyweight combination has the proper regulation at the time it is assembled, and it is not unusual to find that the assembled governor exceeds the tolerance limits by several percentage points after the governor is installed on the prime unit.

Typically, when governor regulation is not within tolerance, this is corrected by such means as a rigid control lever manually adjustable to set the biasing force of the governor spring so that the desired governor regulation is obtained. Exemplary of such rigid control levers are those described in the above-mentioned US. Pat. Nos. 3,534,660 to Glassey, et al.; 2,961,229 to Parks, and 3,145,702 to Parks.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION The invention provides adjustment means for simply and efficiently adjusting governor regulation within a desired range by selectively adjusting the biasing force of a governor spring to compensate for manufacturing tolerances which detract from governor performance. The adjustment means comprise a resilient lever having a cantilevered portion acting against the governor spring and an adjustable fulcrum member for the cantilever which may be selectively positioned to vary the length of the cantilever and thus its effective spring rate. Suitable adjustment of the fulcrum member thereby adjusts governor regulation as desired within a relatively narrow range of tolerance.

It is therefore an object of this invention to provide simple, efficient means for adjusting governor regulation to the desired level within relatively narrow tolerances.

It is another object of this invention to provide simple, efficient means for adjusting governor regulation to compensate for manufacturing tolerances which detract from governor performance.

It is a further object of this invention to provide adjustment means for adjusting governor regulation comprising a cantilevered resilient lever.

Other objects and advantages of this invention will be apparent to those skilled in the art from the following description and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view, with parts in section, of a governor including theadjusting means of this invention;

FIG. 2 is an enlarged fragmentary view of the governor of FIG. 1 illustrating the adjustment means in detail;

FIG. 3 is a detail viewof the adjustment means of FIGS. 1 and 2 in an alternate position; and

FIG. 4 is a view taken along the lines lVlV of FIG. 2. I? 1 DETAILED DESCRIPTION oF THE DRAWINGS With particular reference to FIG. 1, a governor generally indicated at 10 controls the longitudinal position of a fuel pump rack bar 11, and accordingly the adjustment of thefuel pumps, one of which is shown at 12, through a segment gear 13 associated with each'fuel pump and interacting with the rack bar. The governor 10 is enclosed by a governor housing 14 and a fuel pump housing 16, and includes flyweights 17 pivotally mounted on a cylindrical carrier 18 by pins 19. The carrier is mounted for rotation about a cylinder 21 affixed to the fuel pump housing. The cylinnder 21 forms gear teeth as indicated at 22 to provide a pinion in constant mesh with a drive gear 23 secured to a shaft 24 which forms a part of the timing gear train of thhe engine or other main unit (not shown).

The flyweights 17 move outwardly under the influence of increasing engine speed so that their radially inwardly extending arms 26 act against a riser 27 secured to the distal end of the rack bar 11, and tend to cause leftward movement of the rack bar and riser as viewed in FIG. 1. This leftward motion of the rack bar 11 and the riser 27 is resisted by a governor spring 28 acting against the riser and a spring seat 29 slideably engaged on a support member 31 and retained in position thereon by means described below in detail. Thus, when engine speed is increasing, the flyweights 17 move outwardly and their radial arms 26 act against the riser 27 to overcome the spring 28 and cause leftward movement of the rack bar 1 1. Conversely, when engine speed is decreasing, the flyweights 17 move inwardly and the spring 28 tends to return the rack bar 11 to its rightward position. i

The above description isillustrative ofa conventional governor which may usefully be employed in combination with the adjustment means of this invention so that governor regulation may be satisfactorily adjusted to compensate for manufacturing tolerances. Other governors of this type may, of course, also be employed with the adjustment means to obtain the desired governor regulation. The governor 10 further includes adjustment means generally indicated at 32 which permit adjustment of the governor and governor regulation of engine speed. The adjustment means 32 includes a resilient lever 33 cantilevered over a semi-cylindrical fulcrum member 36 which is pivotally mounted on a shaft 37. One end of the resilient lever 33 is adapted to move with lever member 34, as will hereinafter be described, which is fixed to and controls the shaft 37 while the opposite end thereof bears against the spring seat 29 in opposition to the governor spring 28.

As best shown in FIGS. 2 and 3, the fulcrum member 36 includes a first arcuate surface 38 intersecting a second arcuate surface 39 to form a shoulder 41 which acts as a fulcrum for the cantilever of the resilient lever 33. A slot 42 is formed in the arcuate surface 39 and part way around the periphery of the fulcrum member 36, partly within a groove 57 formed in arcuate surface 38, and accommodates a pin or bolt 43 thereadably securable in a bore 44 in the shaft 37; Preferably, the resilient lever 33 comprises a leaf spring forming a series of reverse curves 46, 47 and 48. The curves 46 conforms to the first arcuate surface 38 for engagement therewith as shown in FIG. 2, while the curve 48 bears on the spring seat 29. The curve47is of suitable dimensions to impart the desired range of spring rate to the cantilevered portion of the resilient lever 33 for a particular application. Conveniently, the resilient lever 33 may be secured to the lever member 34 by an additional curve 49 acting against projection 51 fixed between secondary levers 52, 53 which are, in turn, fixed to rotate with shaft 37 and thereby lever member 34 to retain the resilient lever in position thereon. As best shown in FIG. 3, the distal portion 54 of the resilient lever 33 is bifurcated into arms 55, 56 to provide an even bearing balanced application of forces on opposite sides of the spring seat 29. Inoperation, the fulcrum member 36 is rotated to locate the shoulder 41 to provide the cantilevered portion of the resilient lever 33 with the desired spring rate. In the position shown in FIG. 2, the cantilevered portion of the resilient lever has a relatively high spring rate. If, for example, the governor spring 38 produced a regulation of 6 percent with the fulcrum member 36 in the position shown in FIG. 2, and it were desired to reduce governor regulation to the vicinity of 3 percent, it would be necessary to soften the mechanism. This is achieved by loosening the bolt 43 and rotating the fulcrum member 36 counter-clockwise' toward the position shown in FIG. 3. As "the fulcrum member is rotated in this direction, the effective spring length of the resilient lever 33 is increased, thus reducing the spring-rate of the cantilevered portion and the force with which it bears upon the spring seat 29 The force of the governor spring 38 opposing the action of the flyweights 17 is correspondingly reducedv with. the reduction of s pringrate, and governor regulation is thereby decreased. When the fulcrum member is in the desired position, the bolt 43 is retightened.

The overall spring system of the governor and the adjustment means 32 may thus be softened or hardened by appropriate manipulation of the fulcrum member 36 to adjust governor regulation to the desired level within acceptable tolerances.

Although the invention has been described in terms of a specific embodiment, it is apparent that this embodiment may be modified by those skilled in the art to equivalent embodiments without departing from the spirit and scope of this invention. The above descrip' tion describes an illustrative example of this invention and the manner in which it operates, and the invention is not limited thereto, except as specifically pointed out in the claims hereto appended.

What is claimed is:

1. In a governor of the type having a governor spring interacting with a plurality of flyweights to regulate the speed of an engine, adjustment means for adjusting said engine regulation comprising a resilient lever having a cantilevered portion acting against said governor spring and adjustable fulcrum means for regulating the length and thereby the spring rate of said cantilevered portion of said resilient lever, wherein said fulcrum means comprises a semi-cylindrical rotatable member rotatably mounted on a shaft and having a first arcuate surface corresponding to a mating surface of the resilient lever and a second arcuate surface intersecting said first arcuate surface to form a shoulder comprising a fulcrum for said cantilevered portion of said resilient lever.

2. The invention of claim 1 wherein said resilient lever comprises a leaf spring forming a series of reverse curves, one of said curves mating with said arcuate surface, another of said curves secruing said resilient lever to said governor, and the apex of another of said curves bearing on said governor spring through an interdisposed movable spring seat for said governor spring.

3. The invention of claim 2, wherein said spring seat is coaxially disposed on a support member in slideable engagement therewith, and wherein said resilient lever has a bifurcated distal portion bearing against said spring seat, said support member being disposed between the bifurcations of said distal portion of said resilient lever for balanced application of force against said spring seat.

4. The invention of claim 1, wherein said adjustment means comprises an elongated slot in said rotatable member and bolt means therein for adjustably securing said rotatable member to said shaft.

5. The invention of claim 4, wherein said bolt means comprises a bolt threadably secured in said shaft. 60 l l= 

1. In a governor of the type having a governor spring interacting with a Plurality of flyweights to regulate the speed of an engine, adjustment means for adjusting said engine regulation comprising a resilient lever having a cantilevered portion acting against said governor spring and adjustable fulcrum means for regulating the length and thereby the spring rate of said cantilevered portion of said resilient lever, wherein said fulcrum means comprises a semi-cylindrical rotatable member rotatably mounted on a shaft and having a first arcuate surface corresponding to a mating surface of the resilient lever and a second arcuate surface intersecting said first arcuate surface to form a shoulder comprising a fulcrum for said cantilevered portion of said resilient lever.
 2. The invention of claim 1 wherein said resilient lever comprises a leaf spring forming a series of reverse curves, one of said curves mating with said arcuate surface, another of said curves secruing said resilient lever to said governor, and the apex of another of said curves bearing on said governor spring through an interdisposed movable spring seat for said governor spring.
 3. The invention of claim 2, wherein said spring seat is coaxially disposed on a support member in slideable engagement therewith, and wherein said resilient lever has a bifurcated distal portion bearing against said spring seat, said support member being disposed between the bifurcations of said distal portion of said resilient lever for balanced application of force against said spring seat.
 4. The invention of claim 1, wherein said adjustment means comprises an elongated slot in said rotatable member and bolt means therein for adjustably securing said rotatable member to said shaft.
 5. The invention of claim 4, wherein said bolt means comprises a bolt threadably secured in said shaft. 